Existing additive manufacturing solutions (e.g., 3-D printing solutions) may have the potential to disrupt manufacturing in the way that online music and electronic books disrupted their respective industries. 3-D printing may be used for rapid prototyping or point-of-sale printing, and may be used for short production runs or bespoke items, such as custom equipment parts, artificial limbs, dental fixtures, and bridge components, or other devices.
Some 3-D printing solutions date back to the 1970s. Early 3-D printing applied a technique known as fused deposition modelling (FDM), which fuses layer of extruded material upon layer of extruded material to create an object. Later 3-D printing solutions included laser-sintering and power-based approaches. Printed 3-D materials may include masonry, plastics, metals, biodegradable materials, imaging apertures, pharmaceuticals, nanocomposites, microfluids, and other devices. The technology has also been used for preserving and increasing access to historical objects via replication, and has been useful in creating educational excitement.
Several impediments exist that limit the adoption of 3-D printing. One relevant concern is that existing 3-D printers cannot detect product defects, especially defects that render the product unsuitable for the production of safety-critical or performance-critical parts. For such safety-critical items, production costs and delivery times may be affected significantly, to such an extent that the production of bespoke parts may not be feasible.
An existing technology that may be applied to assess 3-D printing is 3-D scanning. 3-D scanning has been used to measure feet to create custom running shoes, evaluate the effect of cosmetic products, uniform sizes, and custom swimwear, for example. 3-D scanning has also been used to detect a variety of changes and defects including changes in skeletal structure, to validate quality of automotive products, or to assess concrete or turbine blades. 3-D scanning solutions may be performed using laser and “white light” techniques. Low-cost solutions have been created, such as using the Xbox Kinect or Raspberry Pi cameras. Some 3-D scanning solutions require scanner movement around an object, whereas others allow the object to remain stationary. In some cases, a portion of an object is removed to allow scanning of the interior structure. This removal of part of the object is known as destructive scanning. In an embodiment, destructive scanning may include removing layers from an object or slicing the object into layers, and re-scanning the object during or following removal of each layer.
Some existing manufacturing solutions use large-run or statistically-driven quality management to monitor manufactured items. This does not properly handle the generation of low-run, customized, and bespoke 3-D printable items. This is problematic, as some quality management systems, such as total quality management (TQM), are highly reliant on being able to characterize and guarantee the quality of their parts. This characterization and guarantee can be performed via inspection, such as by the supplier prior to shipping, or by the buyer upon receipt. As an alternative to inspection, process certification is often preferred, as it may reduce cost levels, such as by removing or reducing inspection time costs, and catching defects earlier in process. However, many quality management systems are directed to post-manufacturing analysis and corrective actions.
When quality is critical, it may be possible to test 3-D printed objects in post-production. However, post-production testing may limit the type of objects that can be produced, as some tests may be destructive. Additionally, given the potential for irregularities in any item, testing a small number of units may not be suitable to certify a batch.
Existing additive manufacturing systems (e.g., 3-D printing systems) lack the capability to assess the quality of the products that they produce. Desktop 3-D printers, for example, may continue printing until they have completed all steps in an object, even though their filament ran out or jammed part way through. These and other manufacturing systems may fail to notice minor defects that could potentially be corrected automatically. For example, in multi-layered 3-D printing, a defect is most easily corrected before a subsequent layer is printed on the defective layer. Existing systems also do not include functionality to identify defects that require manual intervention. For example, a defect may render the object unsuitable for use, and without user intervention, the defect may render any additional time or supplies consumed on the current print wasteful.